﻿/************************************************************************

   Extended Silverlight Toolkit

   Copyright (C) 2010-2012 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://extendedsilverlight.codeplex.com/license

   Please purchase a commercial version of this toolkit if you are using
   it in a commercial product. The commercial versions support the project,
   and also include more features for each control, priority support,
   source code, updates, removed watermark, and a proprietary license.

   Visit http://xceed.com and follow @datagrid on Twitter.

  **********************************************************************/

using System.Collections.Generic;

namespace Xceed.Silverlight.Data
{
  internal class LocalDataSourceEnumerator : DataSourceEnumeratorBase, ICachingEnumerator
  {
    #region Constructor

    internal LocalDataSourceEnumerator(
      IAsyncEnumerator<DataPath> childEnumerator,
      IEnumerable<GroupCacheEnumeratorBase> groupCacheEnumerators,
      IGroupDataHelper dataSourceHelper,
      GroupHandler groupHandler )
      : base( childEnumerator, groupCacheEnumerators, null, dataSourceHelper, groupHandler )
    {
      m_cacheEnumerator = childEnumerator as CacheEnumerator;
    }

    #endregion

    #region ICachingEnumerator Members

    int ICachingEnumerator.CacheSize
    {
      get
      {
        return m_cacheSize;
      }
    }

    void ICachingEnumerator.SetCacheSize( int size )
    {
      if( m_cacheEnumerator != null )
      {
        m_cacheEnumerator.SetCacheSize( size, this.CurrentPosition );
        m_cacheSize = m_cacheEnumerator.CacheSize;
      }
      else
      {
        m_cacheSize = size;
      }
    }

    void ICachingEnumerator.SetCacheSize( int size, double topTrimRatio )
    {
      if( m_cacheEnumerator != null )
      {
        m_cacheEnumerator.SetCacheSize( size, topTrimRatio );
        m_cacheSize = m_cacheEnumerator.CacheSize;
      }
      else
      {
        m_cacheSize = size;
      }
    }

    void ICachingEnumerator.SetCacheSize( int size, SourcePosition topTrimLimit )
    {
      if( m_cacheEnumerator != null )
      {
        m_cacheEnumerator.SetCacheSize( size, topTrimLimit );
        m_cacheSize = m_cacheEnumerator.CacheSize;
      }
      else
      {
        m_cacheSize = size;
      }
    }

    private int m_cacheSize;

    #endregion

    #region Private Fields

    private readonly CacheEnumerator m_cacheEnumerator; //null

    #endregion
  }
}
